Thursday 29 December 2011 15.10 EST
First published on Thursday 29 December 2011 15.10 EST

The daughter of the former Libyan leader Muammar Gaddafi has hired an Israeli lawyer to petition the international criminal court to investigate the circumstances of the death of her father.

Aisha Gaddafi, who fled Libya in August before the capture and killing of her father by opposition forces, claims to have been caused "severe emotional distress" by the images of his death and the treatment of his body.

Nick Kaufman, a former senior prosecutor at the ICC and now an international lawyer based in Jerusalem, wrote to the ICC prosecutor Jose Luis Moreno-Ocampo earlier this month to demand an immediate investigation.

Gaddafi and his son Mutassim, Aisha's brother, "were murdered in the most horrific fashion with their bodies thereafter displayed and grotesquely abused in complete defiance of Islamic law. The images of this savagery were broadcast throughout the world causing my client severe emotional distress," said the letter, which has been seen by the Guardian.

Kaufman demanded answers to a series of questions, including whether the ICC was investigating the circumstances of the deaths, whether it had received reports of postmortem examinations of the bodies, why the ICC had not ordered its own independent postmortem, and whether it was investigating an alleged attack by Nato forces on Gaddafi's convoy shortly before his capture and killing.

"To date, neither Ms Gaddafi nor any member of her family has been informed by your office of the initiation of an investigation into the circumstances surrounding the brutal murders," said the letter, sent on 13 December.

A reply sent a week later from an ICC official, Phakiso Mochochoko, said the Libyan authorities had promised to Gaddafi's death, and that the ICC's prosecutors' office would report on their progress in May.

"The [prosecution] strategy will depend on the activities of the Libyan national authorities and whether they are genuinely carrying out such investigations," the letter said. It added that the prosecutors had a duty of impartiality and "consistently stressed the need to investigate allegations of war crimes committed by different parties to the conflict in Libya".

Kaufman said the term "different parties" included Nato as well the opposing Libyan forces. "We don't think the [present Libyan government] has the capacity or will to investigate this crime. We are demanding an immediate investigation by the ICC."

A delay until May would mean the loss of ballistic and forensic evidence and increased difficulties in identifying objective eyewitnesses, he said.

Gaddafi and his son were captured on 20 October near his home town of Sirte, after their convoy was hit by a Nato air strike. He was shot, beaten and reportedly sodomised by a stick before being dragged through the streets. His bullet-ridden and decomposing body was kept in a cold storage room in Misrata for six days, and viewed by thousands of Libyans, before burial at a secret desert location.

Aisha Gaddafi fled to Algeria with her mother and two brothers soon after the fall of Tripoli. Last month she called for a revolt against Libya's new leaders, saying: "My father has not left, he is always among us. Don't forget the orders of your father urging you to continue fighting, even if you no longer hear his voice."

The ICC issued arrest warrants in June for Gaddafi, his son Saif al-Islam and the former head of state security Abdullah Senussi for crimes against humanity. Saif al-Islam was captured last month and is being held in Libya, where he could be tried, rather than extradited to The Hague.

Kaufman denied reports that Aisha Gaddafi could seek asylum in Israel. "She has not raised the issue of asylum with me, not once," he said, describing it as a ludicrous suggestion.

Kaufman said he had no qualms about representing the daughter of the former Libyan leader. "She is not suspected of or charged with any criminal offence, and she has a legitimate complaint," he said. She had approached him because he was a former ICC prosecutor who had since successfully challenged the international court. "It's nothing to do with the fact that I'm Israeli," he added.